Modified cellulose from chemical fiber and methods of making and using the same

Abstract

This disclosure relates to improved products containing oxidized cellulose. This disclosure further relates to improved methods of making oxidized cellulose in multi-stage bleaching processes, including, for example, in four-stage and three-stage bleaching processes. This disclosure further relates to products made therefrom, including wipe, tissue, towel, and napkin products.

What is claimed is: 
     
       1. A method of making an oxidized cellulose comprising:
 bleaching a cellulosic pulp using a bleaching process consisting of four bleaching stages, wherein at least one stage of the four-stage bleaching process is an oxidizing (OX) stage comprising oxidizing the pulp with at least one peroxide and at least one catalyst under acidic conditions; and 
 wherein the four-stage bleaching process is a sequence chosen from one of D 0 E(OX)D 1 , D 0 ED 1 (OX), D 0 (OX)D 1 (OX), or D 0 (OX)D 1 D 2 . 
 
     
     
       2. The method according to  claim 1 , wherein the at least one catalyst comprises at least one of a copper-containing catalyst and an iron-containing catalyst, and wherein the at least one peroxide is hydrogen peroxide. 
     
     
       3. The method according to  claim 2 , wherein at least one stage of the bleaching process is a carboxylating D stage comprising treating the fiber with a carboxylating agent. 
     
     
       4. The method according to  claim 2 , wherein the four-stage bleaching process is a sequence chosen from one of D 0 E(OX)D 1  or D 0 (OX)D 1 D 2 . 
     
     
       5. The method according to  claim 2 , wherein no the four-stage bleaching process is a sequence chosen from one of D 0 E(OX)D 1 , D 0 ED 1 (OX), D 0 (OX)D 1 (OX), or D 0 (OX)D 1 D 2 . 
     
     
       6. The method according to  claim 2 , wherein the four-stage bleaching process is a sequence chosen from one of D 0 E(OX)D 1 , D 0 (OX)D 1 (OX), or D 0 (OX)D 1 D 2  and wherein the at least one oxidizing stage is followed by at least one carboxylating D stage comprising treating the fiber with a carboxylatinq agent. 
     
     
       7. The method according to  claim 2 , wherein the at four-stage bleaching process is a sequence chosen from one of D 0 (OX)D 1 (OX) or D 0 (OX)D 1 D 2 . 
     
     
       8. The method according to  claim 2 , wherein the four-stage bleaching process is D 0 E(OX)D 1 . 
     
     
       9. The method according to  claim 2 , wherein the four-stage bleaching process is a sequence chosen from one of D 0 ED 1 (OX) or D 0 (OX)D 1 (OX). 
     
     
       10. A method of making an oxidized cellulose comprising:
 bleaching a cellulosic pulp using a bleaching process consisting of three bleaching stages, wherein at least one stage of the three-stage bleaching process is an oxidizing (OX) stage comprising oxidizing the pulp with at least one peroxide and at least one catalyst under acidic conditions, and 
 wherein the three-stage bleaching process is a sequence chosen from one of D 0 (OX)D 1 , DE(OX), or D(OX)E. 
 
     
     
       11. The method according to  claim 10 , wherein the at least one catalyst comprises at least one of a copper-containing catalyst and an iron-containing catalyst, and wherein the at least one peroxide is hydrogen peroxide. 
     
     
       12. The method according to  claim 11 , wherein at least one stage of the bleaching process is a carboxylating D stage comprising treating the fiber with a carboxylating agent. 
     
     
       13. The method according to  claim 11 , wherein the three-stage bleaching process is a sequence chosen from one of D 0 (OX)D 1  or D(OX)E. 
     
     
       14. The method according to  claim 11 , wherein the three-stage bleaching process is a sequence chosen from one of D 0 (OX)D 1  or DE(OX). 
     
     
       15. The method according to  claim 11 , wherein the three-stage bleaching process is D 0 (OX)D 1  and D 1  is a carboxylating D stage comprising treating the fiber with a carboxylating agent. 
     
     
       16. The method according to  claim 11 , wherein the three-stage bleaching process is a sequence chosen from one of D 0 (OX)D 1  or D(OX)E. 
     
     
       17. The method according to  claim 11 , wherein the three-stage bleaching process is D 0 (OX)D 1 . 
     
     
       18. The method according to  claim 1 , wherein at least one of the D stages is a carboxylating D stage comprising treatment with either sodium chlorite and hydrogen peroxide or chlorine dioxide and hydrogen peroxide. 
     
     
       19. The method according to  claim 18 , wherein the four-stage bleaching process is a sequence chosen from one of D 0 E(OX)D 1 , D 0 (OX)D 1 (OX), or D 0 (OX)D 1 D 2  and wherein the at least one D stage comprising treatment with either sodium chlorite and hydrogen peroxide or chlorine dioxide and hydrogen peroxide follows at least one oxidizing stage. 
     
     
       20. The method according to  claim 10 , wherein at least one of the D stages is a carboxylating D stage comprising treatment with either sodium chlorite and hydrogen peroxide or chlorine dioxide and hydrogen peroxide. 
     
     
       21. The method according to  claim 10 , wherein the three-stage bleaching process is D 0 (OX)D 1 , and wherein the D 1  stage is a carboxylating D stage comprising treatment with either sodium chlorite and hydrogen peroxide or chlorine dioxide and hydrogen peroxide.